Field of the Invention
The present invention relates to a solid-state image sensor and camera.
Description of the Related Art
A solid-state image sensor such as a CCD image sensor or a CMOS image sensor is used in a camera such as a video camera or an electronic still camera. Some solid-state image sensors include focus detection pixels. Japanese Patent Laid-Open No. 2013-157883 discloses a solid-state image sensor in which a light blocking portion covering almost half the region of a photoelectric converter is arranged on the photoelectric converter. In such a solid-state image sensor, light having passed through the first region of the pupil of an imaging optical system enters focus detection pixels of the first group, and light having passed through the second region of the pupil enters focus detection pixels of the second group. Focus detection is performed (defocus amount is detected) based on an image detected by the focus detection pixels of the first group and the focus detection pixels of the second group.
When the light blocking portion is provided to cover almost half the region of the photoelectric converter, the edge of an image detected by the focus detection pixels of each group becomes flat in a region where the image height is large, and the focus detection performance may drop or focus detection may fail.